Re: [OT] Denis Ritchie Education

From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: [OT] Denis Ritchie Education
Date	2016-08-02 19:37 +0100
Organization	A noiseless patient Spider
Message-ID	<87oa5bt3tq.fsf@bsb.me.uk> (permalink)
References	(4 earlier) <kfnd1lsjbkd.fsf@x-alumni2.alumni.caltech.edu> <87wpjz68re.fsf@gmail.com> <1b8twfqlko.fsf@pfeifferfamily.net> <87ziovtcl6.fsf@bsb.me.uk> <1b4m73qeh7.fsf@pfeifferfamily.net>

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Joe Pfeiffer <pfeiffer@cs.nmsu.edu> writes:

> Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
>
>> Joe Pfeiffer <pfeiffer@cs.nmsu.edu> writes:
>>
>>> Gareth Owen <gwowen@gmail.com> writes:
>>>
>>>> Tim Rentsch <txr@alumni.caltech.edu> writes:
>>>>
>>>>> Gareth Owen <gwowen@gmail.com> writes: Do you think the computers
>>>>> developed at UPenn and IAS did not include a stored program
>>>>> functionality?  
>>>>
>>>> Paper tape and punch cards are not a "stored program" as the term is
>>>> commonly used in computing history.  You may choose to consider them to
>>>> be so. 
>>>>
>>>> https://en.wikipedia.org/wiki/Stored-program_computer 
>>>>
>>>> "A stored-program computer is one that stores program instructions in
>>>> electronic memory" ... 
>>>>
>>>> "The University of Manchester's Small-Scale Experimental Machine (SSEM)
>>>> is generally recognized as world's first electronic computer that ran a
>>>> stored program—an event that occurred on 21 June 1948. However the SSEM
>>>> ... more a proof of concept predecessor to the Manchester Mark 1
>>>> computer, which was first put to research work in April 1949."
>>>>
>>>> You may choose other definitions to fit your preferred answers.  Whatever.
>>>
>>> I'd quibble with wikipedia's requirement that a stored program computer
>>> needs to use "electronic" memory -- the Harvard machine executed a
>>> program stored on paper tape, but wasn't a computer in the sense that it
>>> wasn't Turing complete.
>>
>> Presumably you mean the Harvard Mark I as there were a series of them up
>> to the Mark IV.  Can you say why it is wasn't Turing complete?  The
>> requirements for completeness are modest (putting aside the far from
>> modest assumption of unbounded resources) so the reason for failing
>> would be significant I think.
>>
>> (It's hard to find enough details on the web to settle this by simple
>> searching -- I did try for a bit.)
>
> As originally built, it couldn't do a conditional branch.  Later it was
> able to conditionally switch between several paper tapes for its
> instructions, but from what I've read that isn't good enough (like you,
> I'd have to get more details on just how it did that to say for myself
> whether it was really Turing complete, but the claims I've come across
> say "no").  Hmmm, looks like Blaauw and Brooks has a chapter about
> it...

Ah, thanks.  I did not know that.  I would rule out (from being a
candidate for the first automatic computer) anything that can't do a
conditional branch (which presumably includes what we'd call a while
loop these days).

-- 
Ben.

Thread

Re: [OT] Denis Ritchie Education "J. Clarke" <j.clarke.873638@gmail.com> - 2016-07-31 05:30 -0400
  Re: [OT] Denis Ritchie Education Tim Rentsch <txr@alumni.caltech.edu> - 2016-07-31 12:40 -0700
    Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-07-31 16:58 -0400
      Re: [OT] Denis Ritchie Education Tim Rentsch <txr@alumni.caltech.edu> - 2016-07-31 15:13 -0700
        Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-07-31 21:21 -0400
          Re: [OT] Denis Ritchie Education Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-01 08:12 -0700
      Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-07-31 16:41 -0600
        Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-07-31 21:24 -0400
          Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-07-31 22:15 -0600
            Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-01 09:38 -0400
              Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-01 10:18 -0600
                Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-01 16:22 -0400
                Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-01 15:05 -0600
                Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-04 14:01 -0400
                Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-04 12:22 -0600
                Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-04 16:47 -0400
                Re: [OT] Denis Ritchie Education "Osmium" <r124c4u102@comcast.net> - 2016-08-04 14:22 -0500
                Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-04 16:52 -0400
                Re: [OT] Denis Ritchie Education "Osmium" <r124c4u102@comcast.net> - 2016-08-04 16:10 -0500
                Re: [OT] Denis Ritchie Education Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-04 20:30 -0400
    Re: [OT] Denis Ritchie Education luser droog <luser.droog@gmail.com> - 2016-07-31 18:20 -0700
    Re: [OT] Denis Ritchie Education Gareth Owen <gwowen@gmail.com> - 2016-08-01 19:52 +0100
      Re: [OT] Denis Ritchie Education supercat@casperkitty.com - 2016-08-01 15:25 -0700
        Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-01 16:38 -0600
          Re: [OT] Denis Ritchie Education supercat@casperkitty.com - 2016-08-01 15:56 -0700
            Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-01 17:41 -0600
            Re: [OT] Denis Ritchie Education Gareth Owen <gwowen@gmail.com> - 2016-08-02 06:22 +0100
      Re: [OT] Denis Ritchie Education Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-01 16:48 -0700
        Re: [OT] Denis Ritchie Education Gareth Owen <gwowen@gmail.com> - 2016-08-02 06:27 +0100
          Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-02 08:42 -0600
            Re: [OT] Denis Ritchie Education Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-02 16:28 +0100
              Re: [OT] Denis Ritchie Education Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-08-02 11:15 -0600
                Re: [OT] Denis Ritchie Education Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-02 19:37 +0100
                Re: [OT] Denis Ritchie Education supercat@casperkitty.com - 2016-08-02 12:08 -0700
                Re: [OT] Denis Ritchie Education Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-02 22:40 +0100
          Re: [OT] Denis Ritchie Education Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-03 06:57 -0700
          Re: [OT] Denis Ritchie Education "J. Clarke" <j.clarke.873638@gmail.com> - 2016-10-30 09:06 -0400
            Re: [OT] Denis Ritchie Education supercat@casperkitty.com - 2016-10-30 12:42 -0700
            Re: [OT] Denis Ritchie Education Gareth Owen <gwowen@gmail.com> - 2016-10-31 18:12 +0000

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